Depth from Focus
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− | * | + | * Publications |
− | * [http://www.ubka.uni-karlsruhe.de/cgi-bin/psview?document=2002/informatik/2 german diploma thesis] about depth of focus (also available as [http://www.ubka.uni-karlsruhe.de/vvv/2002/informatik/2/2.pdf PDF]) | + | ** [http://www.ubka.uni-karlsruhe.de/cgi-bin/psview?document=2002/informatik/2 german diploma thesis] about depth of focus (also available as [http://www.ubka.uni-karlsruhe.de/vvv/2002/informatik/2/2.pdf PDF]) |
− | * Mechrob-paper ''[http://www.shu.ac.uk/mmvl/research/MechRob04-paper.pdf Focus set based reconstruction of micro-objects]'' | + | ** Mechrob-paper ''[http://www.shu.ac.uk/mmvl/research/MechRob04-paper.pdf Focus set based reconstruction of micro-objects]'' |
− | * [http://www.mrt.uni-karlsruhe.de/hz_prj1.php Depth-from-focus applied in forensic science, MRT Karlsruhe] | + | * Further Reading |
− | * Focus stitching software [http://www.hadleyweb.pwp.blueyonder.co.uk/ CombineZ5] and examples at [http://www.micropics.org.uk/ http://www.micropics.org.uk/] | + | ** [http://en.wikipedia.org/wiki/Anaglyph_image Anaglyph images] |
+ | ** [http://www.mrt.uni-karlsruhe.de/hz_prj1.php Depth-from-focus applied in forensic science, MRT Karlsruhe] | ||
+ | ** Ishita De, Bhabatosh Chanda, Buddhajyoti Chattopadhyay: [http://dx.doi.org/10.1016/j.imavis.2006.04.005 Enhancing effective depth-of-fieldnext term by image fusion using mathematical morphology] | ||
+ | * Other Software | ||
+ | ** Focus stitching software [http://www.hadleyweb.pwp.blueyonder.co.uk/ CombineZ5] and examples at [http://www.micropics.org.uk/ http://www.micropics.org.uk/] | ||
+ | |||
[[Category:Mimas]] | [[Category:Mimas]] |
Revision as of 00:34, 16 November 2006
Contents |
Depth from Focus
3D surface metrology
- You need to grab the focus stack with your microscope and digital camera.
- The results will be even better, if the illumination optics of the microscope can project a pattern.
- Non-destructive measurement of surface profiles
- With our experimental settings we observed (of course the result will depend on the quality of the microscope)
- Vertical resolution <math>\ge 0.2\ \mu m</math> (depending on aperture-size, magnification, projection-pattern and the surface properties of the object).
- Lateral resolution <math>\ge 2\ \mu m</math> (depends).
- Open Source (you are free to improve the code yourself if you redistribute it).
In general one can say: The lower the depth of field, the higher the resolution of the reconstruction. With high magnification (assuming constant numerical aperture) the resolution of the reconstruction goes up. The trade-off is that the reconstruction will cover a smaller area. This can be overcome by lateral stitching (e.g. cogwheel below).
Demonstration
Here are some typical microscope images (showing a surface, which has been shaped using a power beam).
Using a focus-stack one can compute images with extended depth of focus:
If the surface can be illuminated properly, one can even do a 3D-reconstruction of the surface:
[[Image:suevit20.png | 180px|3D reconstruction of suevit (1.4MB video)]] |
As the idea for the algorithm was fixed already, it was possible to implement the algorithm as a command-line tool in less than 4 days, using existing Mimas-software (exspecially the operators for boost::multi_array).
As this is a "quick hack", there's still lots of space for improvements.
Download
The software for estimating height-maps and images with extended depth-of-field is available for free (under the LGPL)! You first need to install version 2.0 of the Mimas Real-Time Computer Vision Library to be able to compile and run depthoffocus-0.1 (652 kByte). The software also comes with sample files to generate photo-realistic 3D-reconstruction using POVRay!
Links
- Publications
- german diploma thesis about depth of focus (also available as PDF)
- Mechrob-paper Focus set based reconstruction of micro-objects
- Further Reading
- Anaglyph images
- Depth-from-focus applied in forensic science, MRT Karlsruhe
- Ishita De, Bhabatosh Chanda, Buddhajyoti Chattopadhyay: Enhancing effective depth-of-fieldnext term by image fusion using mathematical morphology
- Other Software
- Focus stitching software CombineZ5 and examples at http://www.micropics.org.uk/